File Permissions in Linux and Unix

File system security (access rights)

You will see that you now get
lots of details about the contents of your directory, similar to the example
below.

Each file (and directory) has associated access rights, which
may be found by typingls -l. Also,ls -lggives
additional information as to which group owns the file (beng95 in the following
example):

-rwxrw-r-- 1
ee51ab beng95 2450 Sept29 11:52 file1

In the left-hand column is a
10 symbol string consisting of the symbols d, r, w, x, -, and, occasionally, s
or S. If d is present, it will be at the left hand end of the string, and
indicates a directory: otherwise - will be the starting symbol of the string.

The 9 remaining symbols
indicate the permissions, or access rights, and are taken as three groups of 3.

The left group
of 3 gives the file permissions for the user that owns the file (or
directory) (ee51ab in the above example);

the middle
group gives the permissions for the group of people to whom the file (or
directory) belongs (eebeng95 in the above example);

the rightmost
group gives the permissions for all others.

The symbols r, w, etc., have
slightly different meanings depending on whether they refer to a simple file or
to a directory.

Access rights on
files.

r (or -),
indicates read permission (or otherwise), that is, the presence or absence
of permission to read and copy the file